1. Field of the Invention
This invention relates to the process of preventing chalkbrood disease amongst leafcutter bees.
2. Description of the Prior Art
Alfalfa seed production is an important industry in the western United States. In recent years, production has increased significantly, primarily because of use of the alfalfa leafcutter bee (Megachilidae family, Megachile rotundata) as a pollinator. Management of the bees has, in itself, become a large and profitable business.
Since the year 1975, however, the leafcutter bees have been increasingly threatened by a contagious disease known as chalkbrood caused by a fungus (Ascosphaera sp.) which spreads by microscopic spores. The disease has cost alfalfa seed growers millions of dollars annually. In the state of Idaho, alone, losses for the year 1979 were approximately six million dollars as a result of an approximately 20 percent decline in leafcutter bee population due to the disease.
The chalkbrood disease turns the body of an infected bee larva almost completely into fungal cells which eventually produce millions of spores. The destroyed larvae, remaining in large part in the nesting holes, serve as primary sources of infection.
As a result of the large loss in seed production, a massive research program has been launched by entomologists. Researchers have tried controlling the disease with various fungicides, with ultraviolet rays and with other forms of radiation, without success. The latest method and probably most practical method, to date, is the bathing of bees in a 1% solution of chlorox. The primary disadvantage of this method is the loss of from 5 to 30% of the bees by either drowning or poisoning. The disease is further prevented, in part, by placing nesting boards in an area protected from the weather, providing proper ventilation and placing boards in a cool, shady area.
Of prior art patents, U.S. Pat. No. 3,775,786 issued to C. Reinert, would appear most relevant.
It is known that tetracycline and sulfathiazole have been used in controlling a disease common amongst honeybees (family Apidae, Apis mellifera); a disease known as American Foulbrood disease. Foulbrood disease, unlike chalkbrood disease, is caused by aerobic bacteria known as Bacillus larvae.